docs: def pivot(self,binned=True):
          """Calculate :ref:`pivot wavelength <pysynphot-formula-pivwv>`
          of the observation.
  
          .. note::
  
              This is the calculation performed when ETC invokes ``calcphot``.
  
          Parameters
          ----------
          binned : bool
              Use binned dataset for calculations. Otherwise, use native dataset.
  
          Returns
          -------
          ans : float
              Pivot wavelength.
  
          """
          if binned:
              wave = self.binwave
          else:
              wave = self.wave
  
          countmulwave = self(wave)*wave
          countdivwave = self(wave)/wave
  
          num = self.trapezoidIntegration(wave,countmulwave)
          den = self.trapezoidIntegration(wave,countdivwave)
  
          if num == 0.0 or den == 0.0:
              return 0.0
  
          return math.sqrt(num/den)